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Carrageenan

Carrageenan suppliers and sourcing guide

Carrageenan is a sulfated galactan extracted from red seaweeds such as Kappaphycus (Eucheuma cottonii), Eucheuma spinosum and Chondrus crispus. Refined carrageenan is extracted with hot alkaline water, filtered and precipitated with alcohol or potassium chloride; semi-refined (processed Eucheuma seaweed) skips the full extraction and keeps cellulose. Grades are sold by type (kappa, iota, lambda) and standardized gel strength.

Also known as
E407 · Irish moss extract · kappa carrageenan · iota carrageenan · lambda carrageenan
Facts checked
November 2026

Forms and grades of carrageenan

Suppliers sell different products under the same name. Specify the one you need.

  • Kappa carrageenan

    Forms firm, brittle gels with potassium; used in dairy desserts and meat systems.

  • Iota carrageenan

    Forms soft, elastic gels with calcium; used in plant-based desserts and gels.

  • Lambda carrageenan

    Non-gelling; thickens cold liquids such as beverages and sauces.

  • Refined vs. semi-refined (PES)

    Refined grades are clear and purer; semi-refined processed Eucheuma seaweed is cheaper, cloudier and labeled differently in some markets.

  • Standardized blends

    Carrageenan cut with sugars or salts, or blended with locust bean gum, to give a set gel strength.

What to check on the COA

Compare each result with your own specification when the lot arrives.

Identity and type
Infrared spectrum or the FCC identification tests to confirm carrageenan and its type.
Sulfate content
Sulfate on a dry basis, which defines carrageenan and separates types.
Gel strength or viscosity
Gel strength in water or milk, or viscosity of a 1.5% solution at 75 °C, per the supplier's method.
Acid-insoluble matter and ash
Purity checks; acid-insoluble matter is much higher in semi-refined grades.
Heavy metals
Lead, arsenic, cadmium and mercury by ICP-MS, since seaweed takes up metals.
Microbiology
Total plate count, yeast and mold, E. coli and Salmonella.

Storage, lots and expiry

Storage and shelf life

Store carrageenan sealed in a cool, dry place; it is hygroscopic and cakes when exposed to humid air. Keep standardized blends away from heat, which can affect added sugars. Shelf life is set by the supplier's specification, often two to three years unopened.

Lots and expiry dates

Gel strength and type vary with seaweed species, harvest and extraction, so standardized grades are blended to a target; record gel strength per lot and test in your system on changes. Record whether a lot is refined or semi-refined, since they are not interchangeable.

Regulatory status

Facts from regulators and standards bodies, each linked to its source.

This is general information, not regulatory advice. Status differs by country and by how the ingredient is used, so check the rules for your product and market.

Carrageenan suppliers

Manufacturers and distributors whose own websites say they sell it.

We are checking carrageenan suppliers now

Every listing is checked against the supplier’s own website before it goes live, so this list fills in over the coming weeks. The specs and COA checklist above are ready today.

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Frequently asked questions

What forms of carrageenan can brands buy?

Common forms include kappa carrageenan, iota carrageenan, lambda carrageenan, refined vs. semi-refined (PES) and standardized blends. Ask each supplier for the specification sheet of the exact grade they quote.

What should the COA for carrageenan include?

Expect identity and type, sulfate content, gel strength or viscosity, acid-insoluble matter and ash, heavy metals and microbiology, each with its method, specification and result for that lot.

How should carrageenan be stored?

Store carrageenan sealed in a cool, dry place; it is hygroscopic and cakes when exposed to humid air. Keep standardized blends away from heat, which can affect added sugars. Shelf life is set by the supplier's specification, often two to three years unopened.

What is the regulatory status of carrageenan?

21 CFR 172.620 permits carrageenan from listed red seaweeds as a food additive in the amount necessary for an emulsifier, stabilizer or thickener, and requires the additive's label to name it carrageenan. 7 CFR 205.605(a) lists carrageenan as a nonsynthetic substance allowed in processed products labeled organic. Health Canada's List of Permitted Emulsifying, Gelling, Stabilizing or Thickening Agents includes carrageenan.

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